Medical researchers in Ottawa have found a "switch" that injured muscles use to build new tissue from their own stem cells, offering the hope of some day rebuilding muscles of people with muscular dystrophy and other muscle diseases.

They aim to design a drug that would act like the body's own chemical switch, transforming dormant stem cells that live in muscles into new, active muscle cells.

If this works it would be far simpler, cheaper and less prone to side-effects that injecting stem cells from a donor, or from other parts of the body. And it would give new strength and a better life to people with muscular dystrophy, multiple sclerosis, ALS, cancer and many other illnesses.

This is the second major discovery in three years for Michael Rudnicki, a senior scientist at the Ottawa Health Research Institute. The already competitive world of stem cell research is buzzing.

He has been juggling phone calls for two days -- from newspapers, from the New England Journal of Medicine, from the magazine New Scientist, and from the garage that's repairing the air conditioning on his 1995 Ford Windstar during an Ottawa heat wave.

The reporters are all eager for the story. The garage, sadly, will need another day.

While he trusts the minivan's technology a little less every day, he has an ever-growing sense of wonder about the human body. It can repair itself.

Children are the best examples, he says: Their muscles can suffer horrible damage in accidents and still come back almost as good as new. But as we age, we lose that ability. No one knows why.

Now he asks: what if we could restore some of that ability to heal?

The key lies in mysterious cells called adult stem cells, which don't do anything most of the time. Until three years ago, scientists weren't even sure they existed. Since then they have realized that the stem cells are embedded all through our muscles where they lie dormant, waiting for a signal to act. When they receive that signal, they turn first into cells called muscle progenitor cells. Then these fuse together into long strands, forming stringy new muscle cells.

But in some cases, the stem cells just lie there and don't form new muscle when a person needs it -- most obviously in muscle-wasting diseases such as muscular dystrophy or ALS.

What the Rudnicki lab has done is identify the signal that kicks the stem cell into action: a molecule called Wnt that carries a signal from one cell to another, much the way a hormone does. And it has taken this a step farther, actually transforming stem cells through this signal to make the finished product, new muscle tissue, first in cells in a glass dish, and later in live mice.

The team, which includes Patrick Seale, an Ottawa graduate student, and Anna Polesskaya, a Russian researcher, has published its results in today's edition of Cell, a major biology journal.

"This is a very important paper for several reasons," all of which increase our understanding of how adult stem cells build healthy new tissue, said Dr. Alan Bernstein, president of the Canadian Institutes of Health Research. This is the federal agency that helped fund the Rudnicki research.

"We still have to learn a lot about how stem cells develop," and what makes them decide to change their form, he said. As the Wnt signal in adults parallels what happens in a growing fetus, this holds hope that doctors can trick stem cells into the vigorous rush of tissue-building that takes place in the womb, he said.

Michael Rudnicki is a biologist, not a medical doctor. He thinks this may be why he has had success with the stem cell discovery, and with another major finding a few years ago related to it, finding a gene called Pax7 that helps the "switching" happen.

Doctors, he says, want to find a new gene or a stem cell that they can transplant into patients and heal them.

Biologists are trained to ask more basic questions: What is this cell? What makes it tick? The therapy part comes later.

"They (other medical researchers) are trying to hit the ball out of the park," he says. "I'm happy to hit a single, and another single, and another single."

This is exciting because adding a new protein (in drug form) is far easier than transplanting new donor cells, or re-engineering genes, to build new muscle. The limitation is obvious: It's still early days, and the technique has never been tested in people. Even the mouse tests are not finished: The scientists have rebuilt some muscle in live mice, but need to learn whether they can build enough. Results so far look good.

And even if the Rudnicki team's technique works, it won't cure muscular dystrophy. It will at best let people resist the effects of the disease and keep a better quality of life longer.

"We have to be really careful not to overplay it," the 44-year-old biologist says. "There are lots of promising things (in research), many of which later go off the rails ... In a couple of years we should know whether this has legs or not."

It is a great news !
I wonder when they will try it with people. I read that in case of ALS all new medicines are tested on people very quickly after finding, baceuse people with ALS have no time to wait. So I hope it will be try with PALS soon.

By the way, this biologist must have Polish origin, cause he has Polish surname.